Our world felt a little less special on Monday, as NASA’s Kepler mission announced the discovery of an “earth-sized” planet orbiting a “sun-like” star.

Yes, another one.

But this new orb merits special status — because it’s the first planet to be officially confirmed to exist in the so-called “habitable zone.” It’s an ideal size. It orbits just the right distance from its star. And its star is a lot like our own sun.

This means that the planet, called Kepler-22b, is the best bet yet to be a place with a thick atmosphere and a wet landscape.

The discovery “is a major milestone on the road to finding Earth’s twin,” said Douglas Hudgins, Kepler program scientist at NASA Headquarters in Washington, visiting Moffet Field’s NASA Ames for the five-day First Kepler Science Conference.

If this all sounds a little familiar, it’s because we’re getting better and better at finding things.

Twice before astronomers have announced near-Earth-size planets in habitable zones, although clear confirmation has proved elusive.

The tally of confirmed and “candidate” planets grows every day. Just a year and a half into Kepler’s planet-hunting mission, there are 28 confirmed planets and 2,326 candidate planets — of which a stunning 1,000 have been found since February.

Of the 54 “habitable” zone planet candidates seen so far, Kepler-22b is the first to be confirmed. This milestone will be published in The Astrophysical Journal.